1. Field of the Invention
The present invention relates to an electrical connector assembly for electrically connecting an electronic package such as a central processing unit (CPU) with a circuit substrate such as a printed circuit board (PCB), and particularly to a land grid array (LGA) connector assembly adapted for receiving an LGA CPU therein and electrically connecting the CPU with a PCB.
2. Description of the Prior Art
Referring to FIGS. 3 and 4, a conventional LGA connector assembly 9 is adapted for electrically connecting a CPU (not shown) having a plurality of metal pads with a PCB (not shown). The LGA connector assembly 9 comprises an insulative base 91, and a lever 92 and a metal clip 93 pivotally mounted to two opposite sides of the base 91 respectively. The lever 92 comprises a pair of locating portions 921, an offset securing portion 922 between the locating portions 921, a medial portion 923 extending perpendicularly from an end of one of the locating portions 921, and a handle portion 924 extending perpendicularly from a free end of the medial portion 923. The metal clip 93 comprises a lip 931 at an end thereof, and a pair of spaced mounting portions 932 extending arcuately from an opposite end thereof. The base 91 is substantially rectangular. A substantially rectangular cavity 911 is defined in a middle of the base 91, for receiving the CPU therein. A portion of the base 91 under the cavity 911 defines a plurality of passageways 916 receiving a corresponding number of contacts 94 therein. A pair of spaced slots 912 is defined in one end of the base 91. The mounting portions 932 of the metal clip 93 are movably received in the slots 912, such that the metal clip 93 is pivotally mounted on the base 91. A trapezoidal recess 913 is defined in an opposite end of the base 91, and a chamber 914 is defined at an end of the base 91 in communication with the recess 913. The locating portions 921 of the lever 92 are pivotally received in the chamber 914, and the securing portion 922 of the lever 92 is received in the recess 913.
In use, the base 91 is mounted to and electrically connected with the PCB. The metal clip 93 and the medial portion 923 are oriented perpendicularly to the base 91, with the securing portion 922 disposed above the locating portions 921. The CPU is mounted in the cavity 911, and the metal pads of the CPU are loosely attached on the corresponding contacts 94 of the base 91. The metal clip 93 is rotated down to loosely contact the CPU. The handle portion 924 of the lever 92 is rotated downwardly, with the medial portion 923 also rotating downwardly. When the securing portion 922 reaches the lip 931 of the clip 93, the securing portion 922 begins to engage with the lip 931. The handle portion 923 is continued to be rotated downwardly, with the securing portion 922 driving the lip 931 downwardly. When the medial portion 923 has reached a horizontal position, the securing portion 922 of the lever 92 is tightly attached on the lip 931, and the metal pads of the CPU are firmly attached on the contacts 94 of the base 91. The LGA connector assembly 9 thus electrically connects the CPU with the PCB.
At present, with the prevailing trend toward miniaturization of computers, the sizes of LGA connector assemblies used in computers are steadily becoming smaller. In contrast, the number of contacts used in LGA connectors is increasing to meet the need for more signal transmission. These considerations bear on the conventional LGA connector assembly 9 as follows. During the rotation of the lever 92 to force the metal pads of the CPU on the contacts 94 of the base 91, the metal clip 93 and the lever 92 exert forces on the base 91. The forces acting on the portions of the base 91 near the slots 912 and at the chamber 914 are larger than those acting on other portions of the base 91. Therefore the base 91 is liable to deform and warp. When deformation or warpage occurs, some contacts 94 cannot firmly contact the metal pads of the CPU, which disrupts the electrical connection between the CPU and the PCB.
In view of the above, a new LGA connector assembly that overcomes the above-mentioned disadvantages is desired.
Accordingly, an object of the present invention is to provide an-electrical connector assembly such as a land grid array (LGA) connector assembly for electrically connecting an electronic package such as an LGA central processing unit (CPU) with a circuit substrate such as a printed circuit board (PCB), wherein the electrical connector assembly has a base that resists deformation and warpage.
To achieve the above-mentioned object, an LGA connector assembly in accordance with a preferred embodiment of the present invention comprises an insulative rectangular base receiving a plurality of electrical contacts, a metal reinforcement covering the base, and a lever and a metal clip pivotally mounted to two opposite sides of the base respectively. The reinforcement comprises a planar portion, two opposite sidewalls depending perpendicularly from two opposite outer edges of the planar portion, a pair of spaced tabs depending perpendicularly from an outer edge of the planar portion, and an elongate beam depending perpendicularly from an opposite outer edge of the planar portion. Eight projecting members depend perpendicularly from two opposite inner edges of the planar portion. The base defines a cavity in a middle thereof, a pair of aligned channels at one end thereof engaging the tabs of the reinforcement, and eight rectangular holes for fittingly receiving the projecting members. Thus, during rotating the lever to engage with the clip to tightly attach a CPU in the cavity of the LGA connector assembly, the base is enough hard to withstand forces from the clip and the lever.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: